Cartridge Loading- Low output M/C

Rauliruegas 5-22-2018
@almarg , I read in the past that from J.Carr. Now, please tell me if you have first hand experiences where you can attest it.

Attest to what?

I don’t see any inconsistency between what I said, what Mr. Carr’s post that I quoted said, and what you quoted from the Lyra website.

The point, generally speaking, is that minimizing the capacitive load seen by an LOMC cartridge is likely to result in optimal resistive loading being lighter than the resistive load that would be optimal if the capacitive load is higher. And in turn the lighter resistive load is likely to be sonically beneficial.

That makes sense based on theoretical analysis that can be performed, and is backed up by statements by Mr. Carr and by Ralph (Atmasphere), who collectively probably have more relevant expertise than the rest of us put together. And for that matter it is consistent with suggestions provided by Keith Herron for his VTPH-2 phono stage, which I use. From its manual:

We highly recommend trying the VTPH-2 in the no load configuration as the unit is supplied for many moving coil cartridges. 47,000 (47K) ohm RCA load plugs are supplied with the unit for optional use. Additional user specified loading plugs can also be purchased with the unit.

The input resistance of the VTPH-2 is nearly infinite when no loading plug is used, yet Mr. Herron suggests trying that configuration when his phono stage is used with "many moving coil cartridges." And that is how I use mine with my Audio Technica AT-ART9 cartridge, after having also tried 1K and 47K. Audio Technica’s load recommendation for the ART9 is "100 ohms minimum."

And contrary to what you seem to be implying, none of this is in any way inconsistent with a recommendation to "determine by listening." It is a general guideline which can provide a useful starting point, and in some cases what can turn out to be an ending point.

Regards,
-- Al

Will 47 ohms work? Or should I start out at 100 ohms?

You have to try it. There is no Standard (unfortunately). The result will be different from Manufacturer to Manufacturer. Phonstage A with 100ohm will not sound identical to Phonostage B with 100ohm...Depends on Design.

Dear @almarg : I understand all what you posted and that's theory behind.

When I said if you have first hand experiences/attest for that what I'm trying to say is that with a normal phono stage design that normally comes with fixed capacitance value for LOMC cartridges and options for the loading impedance . This is what I'm refereing to.

As Syntax pointed out each phono stage comes with way different kind of designs. So what's your advice to audiophiles about? that because they can't change the capacitance value or don't have money to change too the phono cable then what?

Makes no sense advices as the atmasphere about because there are several many other cartridge set up parameters way more important. All of us must work with what we have using it in the best way we can. The capacitance issue has other implications with LOMC but this not the issue but what exist in the market about.

You are happy with the Herron, good for you but are many way better phono stages with different design to Herron. Try to say or imply that a single characteristic makes the " differences " like the capacitance in LOMC cartridges has no sense. The theory has sense but this is not the issue.

I think that analog is full of severe problems fopr we can enjoy it to now start to worry about capacitance. Go figure ! !

As I said, there are other issues extremely more important where we audiophiles have control with out spend money.

Makes sense to you that now all audiophiles must do something on capacitance? because the common sense of J.Carr says something different in his Lyra site.

Again, I'm not against  that theory but about ist real advantage  especially when before the capacitance issue many of us are trying to know how can we  achieve an accurate tonearm/cartridge/TT alignment that even reviewers today some of them just don't understand the theory behind that kind of critical alignment issue.

@krelldog , don't distress. Makes no changes just make the cartridge tests with what you have and follows what syntax posted. You have to try it, makes tests with what you have before any other thing. Forgeret about theory in that specific regards. Some people try to terrorize to all of us simple audiophiles. No J.Carr never did or does.

R.

Hi Raul,

With regard to the OP's situation, all I was basically saying is that he is likely to obtain better results using the 100 pf setting of his phono stage rather than the 570 pf setting, assuming that he optimizes the resistive loading that is used with the 100 pf setting by listening.

Regards,
-- Al 

There is a massive misunderstanding that seems implicit with Raul's post, which is not surprising since Raul  prefers digital audio... no idea why he posts here.

This is not about money, its the physics of why its worth it do to it right, which does not cost any more. If your phono section is requiring that you use loading resistances, follow my suggestions here and above.

Input capacitance is a thing with all phono sections. It can be considered to be in parallel with the cartridge inductance, and so reduces the resonant frequency that is always present, which should be kept as high as possible. If ever there was an argument for a vacuum tube input, this might well be it, since tubes have far less input capacitance.
Alternatively, if one were to use a stepup transformer, the transformer blocks the RFI resonance due to bandwidth limitations and may well be why some people prefer using an SUT with their phono sections. SUTs are their own bag of tricks- to get them to work right, they have to be loaded at their output to prevent the transformer from ringing (distorting). This value is different for every cartridge as each cartridge has a different impedance and transformers transform impedance. Usually the transformer manufacturer will have an idea of what the correct loading will be (a good example in this regard is Jensen, who also makes some of the best SUTs made).

At any rate, keeping the cable capacitance low is important for proper phono reproduction! @krelldog , there are no specs (just 'features') on the page you linked.

If no SUT is used, one should always start with 47K since that is the industry standard and has been for decades. This value is used because its less susceptible to noise that a higher input impedance might be, while easily driven by moving magnet cartridges which are very susceptible to loading at audio frequencies, unlike moving coil cartridges (unless the latter is high output, since its the inductance that causes the susceptibility). From there reducing the loading resistance can be explored if needed.

**The highest value you can use is recommended for best results.**

That can be considered a general rule of thumb.

Again, if the phono section is unstable or has poor overload margins the result will be more ticks and pops. People often ask me how I get such low noise reproduction without ticks and pops and that is the secret. Many people grew up with unstable phono sections (most Japanese phono equalizers made during the 60s, 70s and 80s were unstable) and so just assume that ticks and pops are part of the LP experience, but it does not have to be that way.